1. Field of the Invention
The present invention generally relates to medical devices, methods, and systems. In a particular aspect, the present invention provides devices, methods, and systems for shrinking tissues, and which are particularly useful for treatment of urinary incontinence in a laparoscopic or minimally invasive manner.
Urinary incontinence arises in both women and men with varying degrees of severity, and from different causes. In men, the condition occurs almost exclusively as a result of prostatectomies which result in mechanical damage to the sphincter. In women, the condition typically arises after pregnancy where musculoskeletal damage has occurred as a result of inelastic stretching of the structures which support the genitourinary tract. Specifically, pregnancy can result in inelastic stretching of the pelvic floor, the external vaginal sphincter, and most often, the tissue structures which support the bladder and bladder neck region. In each of these cases, urinary leakage typically occurs when a patient""s intra-abdominal pressure increases as a result of stress, e.g. coughing, sneezing, laughing, exercise, or the like.
Treatment of urinary incontinence can take a variety of forms. Most simply, the patient can wear absorptive devices or clothing, which is often sufficient for minor leakage events. Alternatively or additionally, patients may undertake exercises intended to strengthen the muscles in the pelvic region, or may attempt behavior modification intended to reduce the incidence of urinary leakage.
In cases where such non-interventional approaches are inadequate or unacceptable, the patient may undergo surgery to correct the problem. A variety of procedures have been developed to correct urinary incontinence in women. Several of these procedures are specifically intended to support the bladder neck region. For example, sutures, straps, or other artificial structures are often looped around the bladder neck and affixed to the pelvis, the endopelvic fascia, the ligaments which support the bladder, or the like. Other procedures involve surgical injections of bulking agents, inflatable balloons, or other elements to mechanically support the bladder neck.
Each of these procedures has associated shortcomings. Surgical operations which involve suturing of the tissue structures supporting the urethra or bladder neck region require great skill and care to achieve the proper level of artificial support. In other words, it is necessary to occlude the urethra or support the tissues sufficiently to inhibit urinary leakage, but not so much that normal intentional voiding of urine is made difficult or impossible. Balloons and other bulking agents which have been inserted can migrate or be absorbed by the body. The presence of such inserts can also be a source of urinary tract infections.
For these reasons, it would be desirable to provide improved devices, methods, and systems for treating fascia, tendons, and other support tissues which have been strained, or which are otherwise too long to provide the desired support. It would be especially desirable to provide improved methods for treating urinary incontinence in men and women. In particular, it would be desirable to provide methods for treating urinary incontinence in a minimally invasive manner with few or no percutaneous tissue penetrations, preferably utilizing laparoscopic or least invasive manner to minimize patient trauma. It would further be desirable to provide incontinence treatment methods which rely on the existing bladder support structures of the body, rather than depending on the specific length of an artificial support. It would also be desirable to provide methods which rely on introduction of a relatively simple probe into the urethra or vaginal, where tissue structures supporting or comprising the urethra may be caused to partially shrink in order to inhibit urinary leakage.
2. Description of the Background Art
Method and apparatus for controlled contraction of soft tissue are described in U.S. Pat. Nos. 5,569,242, and 5,458,596. An RF apparatus for controlled depth ablation of soft tissue is described in U.S. Pat. No. 5,514,130.
A bipolar electrosurgical scalpel with paired loop electrodes is described in U.S. Pat. No. 5,282,799. U.S. Pat. No. 5,201,732 describes a bipolar sphincterotomy utilizing side-by-side parallel wires. A disposable electrosurgical instrument is described in U.S. Pat. No. 4,311,145. U.S. Pat. No. 5,496,312, describes an impedance and temperature generator control.
The following patents and published applications relate to the treatment of urinary incontinence. U.S. Pat. Nos. 5,437,603; 5,411,475; 5,376,064; 5,314,465; 5,304,123; 5,256,133; 5,234,409; 5,140,999; 5,012,822; 4,994,019; 4,832,680; 4,802,479; 4,773,393; 4,686,962; 4,453,536; 3,939,821; 3,926,175; 3,924,631; 3,575,158; 3,749,098; and WO 93/07815.
An electrosurgical probe for the controlled contraction of tissues of the joints and for dermatological indicators is described in U.S. Pat. No. 5,458,596. A bipolar electrosurgical probe having electrodes formed over a restricted arc of its distal end for treatment of, e.g., the esophagus, is described in U.S. Pat. No. 4,765,331. An electrosurgical probe for retrograde sphincterotomy is described in U.S. Pat. No. 5,035,696. Other patents describing electrosurgical probes include U.S. Pat. Nos. 5,462,545; 5,454,809; 5,447,529; 5,437,664; 5,431,649; 5,405,346; 5,403,312; 5,385,544; 5,370,678; 5,370,677; 5,370,675; 5,366,490; 5,314,446; 5,309,910; 5,293,869; 5,281,218; 5,281,217; 5,190,517; 5,098,429; 5,057,106; 4,807,620; 4,776,344; 4,409,453; and 373, 399.
The disclosure of the present application is related to co-pending U.S. patent application Ser. No. 08/610,911, filed on Mar. 5, 1996, having a common inventor but assigned to a different entity.
The present invention provides improved devices, methods, and systems for shrinking collagenated tissues, and particularly for treating urinary incontinence. In contrast to prior art methods, the present invention does not rely on implantation of balloons or other materials, nor does it rely on suturing, cutting, or other direct surgical modifications to the genitourinary support tissues. Instead, the present invention relies on delivering energy to a patient""s own pelvic support tissue to selectively contract or shrink at least a portion of that pelvic support tissue, thereby raising the position of the bladder. The energy will preferably be applied across bipolar electrodes to the endopelvic fascia and/or the arcus tendineus fascia pelvis. A variety of devices and methods are provided for applying gentle resistive heating to these tissues without significant injury to the support tissues, or to the surrounding tissue structures.
In a first aspect, the present invention provides a probe for heating and contracting fascia. The probe comprises a shaft having a proximal end and a distal end. First and second electrodes are disposed near the distal end of the shaft. These electrodes are simultaneously engageable against the fascia, and are separated by a predetermined distance which limits a depth of tissue heating. A handle is adjacent to the proximal end of the shaft for manipulating the electrodes from outside the patient body.
The bipolar probes of the present invention will generally include a predetermined electrode diameter and electrode separation distance to limit the depth of tissue heating, and will optionally have a temperature sensor mounted between the electrodes. The probe will often be adapted to heat the fascia to temperatures significantly less than most known electrosurgical devices, and may include a control system which limits the total electrical potential applied between the bipolar electrodes to much lower average power levels than known electrosurgical devices. In fact, the present heating probe may be conveniently energized with a battery pack carried in the proximal handle of the probe.
In another aspect, the present invention provides a least invasive probe for heating and contracting fascia of a patient body. The fascia is adjacent to a tissue layer, and the probe comprises a shaft having proximal and distal ends. An electrode is disposed near the distal end of the shaft and is laterally deployable from a narrow configuration to a wide configuration between the fascia and the adjacent tissue layer. The electrode in the wide configuration is exposed to engage the fascia. The electrode in the narrow configuration is disposed along an axis of the shaft to facilitate axial insertion of the probe. A handle is adjacent the proximal end of the shaft for manipulating the electrode from outside the patient body.
In yet another aspect, the present invention provides a probe for heating and contracting target tissues. The probe comprises a shaft having a proximal end and a distal end. At least one electrode is disposed near the distal end of the shaft. A handle is disposed adjacent the proximal end of the shaft for manipulating the at least one electrode from outside the patient body. The handle supports a battery and circuitry for energizing the at least one electrode with sufficient RF electrical potential to heat and contract the target tissue.
Circuitry for converting a direct current to an alternating current will often be coupled to the battery to provide heating while avoiding nerve and/or muscle stimulation. In many embodiments, a control system will be coupled to the electrode so that the target tissue is raised to a temperature within a predetermined range. The temperature of the target tissue may be determined by a tissue temperature sensor disposed near the electrode (ideally being disposed between bipolar electrodes) and/or by monitoring the impedance, resistance, or other electrical characteristics of the tissue/electrode circuit.
In another embodiment, the present invention provides a probe for shrinking collagenated tissue of a patient body. The probe comprises a shaft having a proximal end and a distal end. A grasper is disposed near the distal end of the shaft, and is adapted to draw a region of the tissue inward so as to reduce tension within the region. An energy applying member is disposed adjacent to the grasper. The energy applying member is capable of heating the tissue while the tension is reduced so that the tissue contracts, but without substantially ablating the tissue.
The present invention also provides a method to treat a hyperextending support tissue of a patient body. The hyperextending tissue has a tissue depth, and the method comprises electrically coupling the first electrode to the hyperextending tissue. A second electrode is also electrically coupled to the hyperextending tissue, and an electrical potential is applied across the electrodes while controlling a separation between the first and second electrodes. As a result of this separation control, an electrical current within the hyperextending tissue heats and shrinks the hyperextending tissue, but heating of tissue beyond the tissue depth is minimized.
The present invention also provides a method to treat urinary stress incontinence. The method comprises introducing a probe into a patient body and aligning the probe with a pelvic support tissue within the patient body. The probe is energized to heat and contract a portion of the pelvic support tissue.
In most embodiments, a portion of the pelvic support tissue is gently and resistively heated to between about 60xc2x0 C. and 110xc2x0 C., often being between about 60xc2x0 C. and 80xc2x0 C., by applying an electrical potential across the electrodes, the electrodes being adapted to engage the fascia surface. This gentle bipolar resistive heating will often be targeted at fascia. Such contraction of the fascia can raise and/or reposition the bladder within the patient body when the fascia is heated to a depth of less than about 2.8 mm, preferably to a depth of less than about 2.0 mm, thereby minimizing collateral injury to the surrounding tissues. The heating depth can be precisely limited by controlling the diameter of the electrode surfaces (electrode surface diameter typically in the range from about 0.25 mm to about 4.0 mm, often being from about 0.25 mm to about 2.0 mm) and the ratio of the spacing between the electrodes to the electrode surface diameter (the spacing typically being between about 1.0 and 4.0 times the surface diameter). Advantageously, a preferred separation distance of between about 2 and 3 times the electrode surface diameters will provide an effective heating depth of about 2 times the electrode surface diameter. Surprisingly, sufficient RF energy for such targeted heating can be provided by a battery pack within a handle of the probe, the battery typically providing between about 5 and 20 watts.
In a second aspect, the present invention provides an endoscopic method for treating urinary stress incontinence. The method comprises introducing a probe into a patient body, and optically imaging the probe and a target tissue. The target tissue comprises a portion of an endopelvic fascia or an arcus tendineus fascia pelvis. The electrode is positioned against the target tissue, and energized to heat and contract the target tissue, without substantially ablating the target tissue.
Once again, heating will often be limited in depth through the use of a bipolar probe having a predetermined electrode diameter, spacing between the electrodes, and power. Heating can be monitored and/or controlled, optionally using feedback from a temperature sensor mounted between the electrodes. Advantageously, repeatedly sweeping the electrodes across the endopelvic fascia can raise the bladder by discrete increments, typically by between about 0.1 and 3.0 mm with each sweep of the electrodes.
In another aspect, the present invention provides a least invasive method for controllably shrinking fascia. The method comprises inserting a probe into a patient body while the probe is in a narrow configuration. The probe has first and second electrodes, and is expanded to a wider configuration to deploy at least one of the first and second electrodes. The deployed electrodes are engaged against the fascia, and an electrical potential is applied across the electrodes to heat and contract the fascia disposed therebetween.
In yet another aspect, the present invention provides a method for treating a hernia. The hernia comprises a structure which protrudes through a containing tissue. The method comprises applying sufficient energy to the containing tissue adjacent the hernia to heat the containing tissue so that the containing tissue contracts. The contraction mitigates the hernia, but the heat does not substantially ablate the containing tissue.
In another aspect, the invention provides an abdominoplasty method for tightening an abdominal wall. The abdominal wall comprises a fascia, and the method comprises applying sufficient energy to the abdominal wall to heat the fascia so that the abdominal wall contracts. The heat is applied without substantially ablating the abdominal wall and adjacent tissues.
In yet another aspect, the invention provides a method to treat a hyperextending collagenated support tissue of a patient body. The method comprises grasping a region of the hyperextending tissue and drawing the hyperextending tissue inward so as to decrease tension in the region. At least a portion of the drawn region is heated so that the region shrinks, wherein the region is heated without substantially ablating the hyperextending tissue.
In yet another aspect, the invention provides a kit for shrinking a target collagenated tissue within a patient body. The target tissue has a tissue depth, and the kit comprises a probe and instructions for operating the probe. The probe includes a shaft having a proximal end and a distal end. First and second electrodes are disposed near the distal end of the shaft, the electrodes defining a separation distance therebetween. The instructions include the steps of electrically coupling the first and second electrodes with the target tissue, and heating and contracting the target tissue without ablating the target tissue by directing an electrical current flux through the target tissue between the electrodes. The separation distance substantially limits heating beyond the target tissue depth.
In yet another aspect, the invention provides a kit for treating urinary stress incontinence of a patient with a lax pelvic support structure. The kit comprises a probe having a heating element and instructions for operating the probe. Instructions include the steps of coupling the heating element to the pelvic support structure, and applying an amount of energy with the heating element to the pelvic support structure. The energy is sufficient to cause shrinkage of the pelvic support structure, and the shrinkage inhibits urinary incontinence.
In yet another aspect, the invention provides a kit for treating a hernia. The hernia comprises a structure which protrudes through a collagenated containing tissue. The kit comprises a probe having a heating element and instructions for operating the probe. The instructions include the steps of coupling the probe to the containing tissue, and applying an amount of energy from the probe to the containing tissue. The energy is sufficient to heat the containing tissue so that the containing tissue shrinks to mitigate the hernia.
In one exemplary embodiment of the present method, energy is applied from within the patient""s urethra, typically by inserting an energy-applying probe into the urethra without having to employ any percutaneous or transmucosal penetrations or incisions. When using such a urethral probe, the energy will typically be applied directly to the urethral wall, either to a single location aligned with the urethral sling or to at least two sites including a first site upstream of the urethral sling and a second site downstream of the urethral sling. By xe2x80x9curethral sling,xe2x80x9d we mean those supporting tendons and other tissue structures which extend from the pubic bone downward beneath the urethra and urethral sphincter. Application of energy at such location(s) acts to shrink tissue adjacent the urethral lumen and to provide selective xe2x80x9ckinksxe2x80x9d or closure points at which the urethra can be closed.
In an alternative exemplary embodiment, energy-applying elements are penetrated directly into the pubococcygeal muscles, the iliococcygeal muscles, and/or detrusor urinae muscles (and adjacent fascia) which support the urethra and urinary sphincter. By applying energy directly into these supporting muscles and tissue structures, the muscles can be contracted to provide improved urinary continence. In particular, sufficient muscular integrity can be provided so that urinary leakage does not result from transient increases in intra-abdominal pressure as a result of stress. In the illustrated embodiment, the electrodes are penetrated into the target muscles through the vagina, typically using an introducer having an array of extensible electrodes arranged to contact the target muscles and/or tendons.
In these exemplary embodiments, the energy will typically be applied using an electrode capable of delivering radio frequency (RF) energy directly against the urethral wall or into the supporting tissues in a monopolar or bipolar manner. In the first embodiment, electrodes will usually be surface electrodes, i.e., adapted to contact the luminal wall of the urethra without penetration. In the second embodiment, the electrodes are fashioned as needles or other penetrating members which can penetrate into the urethral wall by a desired distance. In addition to electrodes, the heat-applying elements can be optical fibers (for delivery laser or other light energy), resistive heating elements, inductive heating elements, microwave heating elements, or any other device which can be externally powered to heat tissue to the temperatures and for the times discussed below.
The methods of the present invention may also be performed using devices and systems which access the treated tissue structures from sites other than the urethra or vagina. For example, energy-applying probes can be introduced percutaneously from the patient""s abdomen to a desired treatment site, for example the pubococcygeal muscle and tendon, or may alternatively be introduced through the rectum. Alternatively, in female patients, the energy-applying probes can be transmucosally introduced through the vagina, as discussed above. For the purposes of the present invention, it is necessary only that the energy be delivered to a target tissue structure in a manner which permits heating of the tissue to a desired temperature and for time sufficient to contract the tissue by a desired amount.
In addition to RF energy, the devices, systems, and methods of the present invention can rely on other energy sources, such as microwave, light (laser) energy, electrical resistance heating, the delivery of heated fluids, the focusing of ultrasound energy, or any other known energy delivery technique which can be targeted to specific tissue and raise the tissue temperature to the desired range.
When energy is applied directly to the luminal wall, it will be desirable to control the resulting cross-sectional area of the urethra. Usually, the cross-sectional area will be reduced. Control of the amount of reduction can be effected, for example, by placing the energy-applying elements, such as RF electrodes, on an expandable member which can initially be expanded to contact the elements against the luminal wall. As the luminal wall shrinks, the cross-section area of the expandable member can also be reduced. Alternatively, in instances where the energy is being applied to contract adjacent tissue structures, it may be necessary to further expand the expandable member carrying the electrodes to maintain contact. A variety of specific configurations can be utilized.
In some embodiments, devices according to the present invention will comprise a probe body having a proximal end and a distal end. The body will preferably have a length and diameter selected to permit introduction into the urethra or vagina so that the distal end can be positioned adjacent to the urethral sling or target tissues. One or more electrodes are disposed on the distal end of the probe body to apply energy into the urethral wall in the region of the urethral sling and/or into the tissue structures which support the urethral sling. A connector is provided on the proximal end of the probe body to permit connection to an appropriate power supply. The probe body will typically have a length in the range from 5 cm to 20 cm with electrode lengths in the range from 0.3 cm to 7 cm. The probe body will usually have a diameter in the range from 1 mm to 6 mm. The body will usually be flexible, but could also be rigid. The body should have sufficient torsional rigidity to permit rotational orientation and alignment of the probe within the urethra. The probe will include at least a single electrode, and will often include two or more electrodes which can be connected to the power supply in a monopolar or a bipolar fashion. The electrodes may be surface electrodes (for engaging the urethra wall) or tissue-penetrating electrodes for applying energy into the urethra-supporting tissues. In a specific embodiment, the probe will include two axially-spaced apart electrodes which are positioned and configured so that they will be aligned on the upstream and downstream sides of the urethral sling when applying energy within the urethra. The probe may further comprise an expansion member, such as an expandable balloon, carrying at least one of the electrodes on the catheter body. In a second specific embodiment, the probe includes an array of extensible, tissue-penetration electrodes disposed to penetrate target tissues from the vagina.